This invention concerns a filtration assembly, and particularly but not exclusively a filtration assembly for sealing the ends of hollow sheeting.
Multi-wall sheeting is commonly used as a roofing material for conservatories, awnings, carports etc., or in other applications such as a walling material. Characteristically it obtains its strength by virtue of its construction which is usually in the form of a laminated cell structure. This structure is generally quite open, and is usually exposed to atmosphere at sheet ends.
In for instance its use as a roof covering the multi-wall sheeting is exposed to a wide range of moisture and temperature conditions as well as internal condensation. The various joints and seals are therefore critical to the integrity of the roof. Of great importance is the requirement to prevent water; insects; dust particles; pollen, fungal and algae spores from gaining entrance to the internal cells of the laminate cell structure of the roofing plastic. Once established within the laminate these can cause unsightly growths which are extremely difficult to eliminate.
According to the present invention there is provided a filtration assembly, the assembly comprising a length of tape of a material which is permeable to air but generally prevents insects; dust particles; pollen, fungal and algae spores passing therethrough; the tape comprising a central portion extending along its length and locatable over an open end of hollow sheeting, and side portions extending longitudinally on either side of the central portion, the side portions having adhesive means on the tape to enable said portions to adhere to the hollow sheeting on either side of the open end.
The material is preferably, such that water impacting thereagainst will generally not pass through, but water can soak therethrough.
The adhesive means preferably comprises respective layers of adhesive.
The adhesive is preferably substantially at least partially soaked into the material in said side portions.
The adhesive is preferably waterproof, is preferably pressure sensitive, and desirably is a hot melt adhesive. The adhesive may be coloured, and desirably red or brown.
Alternatively the adhesive may be of the type which sets from a solution. The adhesive may comprise an acrylic.
In an alternative embodiment the adhesive means comprises respective strips of double sided adhesive tape.
The material is preferably non-woven and may be spun bond. The material is preferably fused together at a number of discrete locations, which locations may be provided in a regular pattern. The material may comprise polypropylene or polyester. The material is preferably of a type to inhibit fungal growth therein. The material preferably includes a UV resistant additive.
The invention also comprises a filter tape according to any of the preceding seven paragraphs.
The tape is preferably provided in the form of a roll and may comprise a removable backing layer. The backing layer may comprise high density polythene treated with silicone. The backing layer may be wider than the material. The backing layer may be in two discrete parts, each covering a respective one of the side portions.
The invention further comprises a method of making a filter tape according to either of the preceding two paragraphs, the method comprising applying the adhesive onto the material into the areas corresponding to the side portions.
Where the adhesive is of the hot melt type, the adhesive is preferably melted prior to application.
The adhesive is preferably applied as a bead along each side of the material.
After application of the adhesive the tape is preferably squeezed to force the adhesive into the material. The tape may pass between two rollers to apply the squeezing force. As the material passes between the rollers the backing layer is preferably applied onto the material.
Two or more lengths of tape may be simultaneously formed on a double width piece of material with a respective side portion of each length of tape being formed as a double width of adhesive covered material, with the double width tape subsequently being cut into separate lengths.
The invention still further comprises a method of sealing hollow sheeting, the method comprising applying a tape according to any of the preceding seven paragraphs over the open end or ends of the sheeting.